The Way We Know
- He who says "nothing can be known" knows nothing.
- All sensations are true.
1. He Who Says "Nothing Can Be Known" Knows Nothing.
Knowledge is possible, and the claims of the Skeptics that nothing can be known are absurd and self-contradictory.
The second poisonous doctrine that Epicurus identified is known to us today as Radical Skepticism. Skeptics hold that nothing in life can be known with confidence. The Skeptics of Epicurus' time argued, primarily due to their contention that the senses cannot be trusted, that we can never be certain of anything, and at most some things are "probable." Even something as obvious as the expectation that if you jump off a canyon wall you will fall to your death is not certain to such philosophers, it is merely "probable."
Epicurus saw that this confidence-destroying doctrine suffers much the same flaw as Determinism - it is self-contradictory nonsense. Anyone who is ridiculous and absurd enough to advocate that "nothing can be known" is taking you for a fool, because he expecting you to accept that he knows that "nothing can be known." Epicurus held that that such arguments should not be taken seriously, any more than you should seriously accept the argument from a living person that it would be better never to have been born.
Lucretius spoke for Epicurus in writing: " Again, if any one thinks that nothing is known, he knows not whether that can be known either, since he admits that he knows nothing. Against him then I will refrain from joining issue, who plants himself with his head in the place of his feet. And yet were I to grant that he knows this too, yet I would ask this one question; since he has never before seen any truth in things, whence does he know what is knowing, and not knowing each in turn, what thing has begotten the concept of the true and the false, what thing has proved that the doubtful differs from the certain? \[Book 4:469\]
- Citations:
- Lucretius 4:469
- [469] Again, if any one thinks that nothing is known, he knows not whether that can be known either, since he admits that he knows nothing. Against him then I will refrain from joining issue, who plants himself with his head in the place of his feet. And yet were I to grant that he knows this too, yet I would ask this one question; since he has never before seen any truth in things, whence does he know what is knowing, and not knowing each in turn, what thing has begotten the concept of the true and the false, what thing has proved that the doubtful differs from the certain?
- Diogenes of Oinoanda, Fragment 5
- Smith: "Now Aristotle and those who hold the same Peripatetic views as Aristotle say that nothing is scientifically knowable, because things are continually in flux and, on account of the rapidity of the flux, evade our apprehension. We on the other hand acknowledge their flux, but not its being so rapid that the nature of each thing [is] at no time apprehensible by sense-perception. And indeed [in no way would the upholders of] the view under discussion have been able to say (and this is just what they do [maintain] that [at one time] this is [white] and this black, while [at another time] neither this is [white nor] that black, [if] they had not had [previous] knowledge of the nature of both white and black."
- Lucretius 4:469
- Notes:
2. All Sensations Are True.
The senses report what they observe truthfully and without opinion of their own. Error is in what the mind does with the senses, not in the senses themselves.
If Skepticism and Determinism are false, what did Epicurus advocate instead? Epicurus saw that much of the error of conventional thinkers arises from their contention that the faculties given us by nature are incapable of ascertaining truth, and that we have no need of divine revelation or abstract syllogistic logic to determine what is really true. Epicurus vigorously rejected these assertions, and held that the faculties given to us by nature - the five senses, the feelings of pleasure and pain, and the mental anticipatory faculty of prolepsis - are fully sufficient for living in accord with nature.
Epicurus identified that the perceptions of our natural faculties are not at all the same thing as the opinions which we form after processing those perceptions in our minds. Our natural faculties report their perceptions to the mind "truly," in the sense of "honestly," without adding any overlay of opinion of their own. Neither the eyes nor the ears nor any other faculty have any memory, and they simply relay to the mind what they perceive at any moment. It is the mind which turns perceptions into opinions. The eyes do not tell our minds what they see and the ears do not tell our minds what they hear, and so on. Truth and error is in the mind's formation of opinion, not in the faculties given by nature.
The task of determining truth is that of the mind, which requires that we understand both nature and how our faculties process the perceptions provided to us by nature. Our faculties are our only direct contacts with outside reality. As Lucretius wrote as to our "feelings" in general: " For that body exists is declared by the feeling which all share alike; and unless faith in this feeling be firmly grounded at once and prevail, there will be naught to which we can make appeal about things hidden, so as to prove aught by the reasoning of the mind." (Book 1:418)
Epicurus held that the Natural Faculties are (1) The Anticipations Or "Prolepsis", (2) The Five Senses, and (3) The Faculty Of Pleasure And Pain. Epicurus held that Illusions Do Not Invalidate The Senses, and that we must consider not only what the eyes, ears, nose, tongue, and sense of touch tell us, but also what our minds receive directly in the form of Images from the outside world.
Epicurus taught that we should defer to the Priority Of Nature Over "Logic," and that we should reject "Dialectic" as a source of knowledge. He taught the importance of Practical Deductive Reasoning, of Clarity, and of "Waiting" before making a decision where multiple possibilities that are consistent with observation support different conclusions. Epicurus held that in some cases we cannot obtain certainty and the elmination of all but one possibilities, so we must at times allow that Multiple Possibilities may be true. The selection of one possibility among many, when many are equally supported by the evidence, is therefore seen as arbitrary and capricious.
- Major Implications: Error does not occur in the senses, but in the mind in forming opinions about what the sensations are reporting.
- Citations:
- Epicurus to Herodotus 38 - [We] must keep all our investigations in accord with our sensations, and in particular with the immediate apprehensions whether of the mind or of any one of the instruments of judgment, and likewise in accord with the feelings existing in us, in order that we may have indications whereby we may judge both the problem of sense perception and the unseen. ... Moreover, the universe is bodies and space: for that bodies exist, sense itself witnesses in the experience of all men, and in accordance with the evidence of sense we must of necessity judge of the imperceptible by reasoning, as I have already said.
- Lucretius 1:418 - For that body exists is declared by the feeling which all share alike; and unless faith in this feeling be firmly grounded at once and prevail, there will be naught to which we can make appeal about things hidden, so as to prove aught by the reasoning of the mind.
- Lucretius 4:478 - You will find that the concept of the true is begotten first from the senses, and that the senses cannot be gainsaid. For something must be found with a greater surety, which can of its own authority refute the false by the true. Next then, what must be held to be of greater surety than sense? Will reason, sprung from false sensation, avail to speak against the senses, when it is wholly sprung from the senses? For unless they are true, all reason too becomes false.
- Torquatus speaking for Epicurus in On Ends 1:64 - Moreover, unless the constitution of the world is thoroughly understood, we shall by no means be able to justify the verdicts of our senses. Further, our mental perceptions all arise from our sensations; and if these are all to be true, as the system of Epicurus proves to us, then only will cognition and perception become possible. Now those who invalidate sensations and say that perception is altogether impossible, cannot even clear the way for this very argument of theirs when they have thrust the senses aside. Moreover, when cognition and knowledge have been invalidated, every principle concerning the conduct of life and the performance of its business becomes invalidated.
Epicurus to Herodotus 51 - (Yonge) "And, on the other side, error could not be possible, if we did not receive some other motion also, a sort of initiative of intelligence connected, it is true, with direct representation, but going beyond that representative. These conceptions being connected with direct perception which produces the representation, but going beyond it." - Epicurus On Nature Book 28, Sedley trans, fr. 13, col. 6 inf. - “I also frequently reflected that if, when I raised difficulties which someone might have turned against us, he should claim that what used to be assimilated from ordinary language was the same as used to be practiced in the written work, many might well conclude that in those days false opinion was represented in that language, whether through an empirical process, an image-based process, or a theoretical process, or through a non-empirical process, not following one of our current divisions, but simply arising from an internal movement; but that now, because the means of expression is adapted to additional ends, discrimination provides a lead towards the truth. However, let no one ever try to get even with you by linking with you any trace of this suspicion; but [turn] to the entire faculty of empirical reasoning...
- (Aetius 4.8.10) "Leucippus, Democritus, and Epicurus say that sensation and thought arise in the soul from images that approach from outside, for neither of these can occur to anyone without the image falling upon him."
- (Aetius 4.9.5 - 6) "Epicurus says that every sensation and every impression is true, but of the opinions some are true and some false; and sensation gives us a false picture in one respect only, namely with regard to objects of thought; but the impression does so in two respects, for there is impression of both sense objects and objects of thought. Parmenides, Empedocles, Anaxagoras, Democritus, Epicurus, and Heraclides say that the particular sensations of their own object occur in accordance with the matching sized of the pores, each of the sense objects corresponding to each sense."
- Notes:
- Discussion Forum
3. Change Is Constant, But Not So Fast That Knowledge Is Impossible.
Those who say that the existence of change means that nothing is knowable are speaking absurdly and falsely. The universe does constantly change, but not at so fast a rate that we are not able to grasp that which is real to us.
4. The Tests Of Truth Are The Five Senses, The Prolepses (Anticipations), And The Feelings Of Pleasure And Pain.
That which is true to us is determined through the proper use of the five senses, the mind's ability to recognize patterns, and the feelings of pleasure and pain, not through dialectical logic or divine revelation.
5. Those Things At The Perceptible Level Which We Establish Through Our Senses, Prolepses, And Feelings Are No Less Real Than Those Things At The Imperceptible Level Which We Establish Through Deduction.
The qualities and properties of the things that the senses reveal to us are no less true, and no less real, than the conclusions of logic about the atoms and void from which the things around us are made.
Key Takeaways:
About many important things knowledge is possible. It is absurd for radical skeptics to argue that nothing at all can be known, because he who argues that nothing can be known is making an argument that is self-contradictory.
The conclusions about which we are confident are those which are validated by evidence obtained through the primary faculties given us by Nature, which are (1) the five senses, (2) the feelings of pleasure and pain, and (3) the pattern-recognizing faculty called "anticipations" (from the Latin) or "prolepsis" (from the Greek).
These natural faculties are reliable sources of knowledge because they report to us honestly without adding any opinions of their own.
The phrase "All sensations are true" is correct from the perspective that the senses report "truly," in the sense of "honestly" without bias or prejudice.
If we lose the courage to trust our senses as the basis of our knowledge, we lose our grasp not only on proper reasoning, but also our grasp on life itself.
Where the evidence provided by the senses, feelings, and anticipations is conflicting or insufficient to arrive at a single conclusion, it is appropriate to "wait" before accepting any conclusion as true, and where multiple conclusions are consistent with the evidence, it is appropriate to hold all of them as possibly true until evidence becomes available by which only one can be selected as true.
II. Canonics - Knowledge Is Possible And Essential To Happiness*
And he taught us that unless, at the very first, we have confidence in our senses as to those things which are clear and apparent to us, there will be nothing to which we can appeal when we seek to prove, by reasoning of the mind, anything about those things which are hidden. (Lucretius Book 1, line 420) -5
Thus the wise man will hold firmly to that which is true, and he will not be a mere skeptic. [(Diogenes Laertius, Book X)]
Yet there are some men who will claim that nothing at all can be known. As for these, they know not whether even their own claim can be known, since they admit that they know nothing. [(Lucretius Book 4)]
We therefore decline to argue with men who place their head where their feet should be. And yet, even if we granted their claim that they know nothing, we would still ask these questions: [(Lucretius Book 4)]
Since they have never yet seen any truth in any thing, how do they know what "knowing" and "not knowing" are? What is it that has produced in them this knowledge of the true and the false? What is it that has proved to them the difference between the doubtful and the certain? [(Lucretius Book 4)]
That which is able to refute the false must by nature be provable with a higher certainty to be true. And what can fairly be accounted of higher certainty than sensation? [(Lucretius Book 4)]
Can reasoning alone contradict the senses, when reasoning itself is wholly founded on the senses? If the senses are not true, all reasoning is rendered false as well. [(Lucretius Book 4)]
So if by reasoning you are unable to explain why a thing close at hand appears square, but at a distance appears round, it is far better for you to state that you do not know the reason, rather than to let slip from your grasp your confidence in sensing those things that are clear. [(Lucretius Book 4)]
For if you lose your confidence in your senses, you will ruin the groundwork and foundation on which all of your life and existence rest. [(Lucretius Book 4)]
Not only would reason collapse, but life itself would fall to the ground, were you to lose confidence in your senses and fail to use them to shun those pitfalls in life which must be avoided. [(Lucretius Book 4)]
Just as when you erect a building, if your ruler is crooked, your square is untrue, and your level is sloped, then your construction will be faulty, without symmetry, and leaning, with its parts disposed to fall - all ruined by the first erroneous measurements. [(Lucretius Book 4)]
So too will all your efforts at reasoning about things be distorted and false if the sensations on which your reasoning is based are unreliable. [(Lucretius Book 4)]
Therefore, as we reason, we must grasp firmly the ideas which we attach to words, so that we may thereafter be able to refer to those words with confidence, and not leave everything uncertain, or go on explaining to infinity with words devoid of meaning. [(Epicurus, Letter to Herodotus)]
Thus while we direct our greatest and highest interests by reason throughout our whole life, we do not rely either on dialectical reason or logic as our ultimate Canon of Truth. [(Epicurus Doctrine 16, Epicurus' Letter to Herodotus, Diogenes Laertius Book 10)]
Instead, the faculties which constitute our Canon of Truth are our senses, our preconceptions, and our feelings of pleasure and pain, for it is by means of these that we test those things which are true, and we determine which are obscure and need confirmation. [(Epicurus' Letter to Herodotus)]
For only when those things which are clear to us are understood is it time to consider those things which are obscure. [(Epicurus' Letter to Herodotus)]
Now, apply your mind, for a new question struggles earnestly to gain your ears, a new aspect of things is about to display itself. [(Lucretius Book 2)]
Do not be dismayed by the novelty of my words: weigh these matters with keen judgment, and if they seem to you to be true, embrace them, or if they be false, gird yourself to battle them. [(Lucretius Book 2)]
Just as dogs discover by smell the lair of a wild beast that is covered over with leaves, you, by yourself alone, must learn to see one thing after another, and find your way into dark corners to draw forth the truth. [(Lucretius Book 1)]
Think carefully on these things, and then, one step after another, the true path will grow clear. Not even the darkest night will rob you of the road, for each step will light the torch for the next. [(Lucretius Book 1)]
The last of the three major divisions of Epicurean philosophy is that of Ethics - How To Live.