We have said that it is not possible to achieve scientific knowledge through demonstration unless we know the premises that are primary and immediate … With regard to these starting-points, it would be strange if we possessed them all along, since then we would possess knowledge superior to demonstration without being aware of it. But if, by contrast, we acquire them, and did not possess them earlier, how would we come to know them and learn them in the absence of any pre-existing knowledge? That is impossible, as we said earlier with regard to demonstration.1 Thus it is clearly impossible either for us to possess them all along, or for us to acquire them if we are ignorant and have no predisposition for knowledge. So we must already have some capacity …
This capacity evidently belongs to all animals, since they have an innate power of discernment – what we call sense-perception. Though it is innate, there are some animals in which the sense-impression persists, while in others it does not. For the latter group … there is no knowledge outside the act of perceiving; but others can retain something in the mind after perceiving it. And when this happens frequently, we get a difference arising as a result of the retention, some come to develop a logos2 and others do not.
Thus from sense-perception there arises memory; and when there is repeated memory of the same thing, there arises experience (for though there are many memories, they make up a single experience). And from experience – the whole universal now established in the mind (the one distinct from the many, whatever is one and the same in all the many instances) – there arises the starting-point of a skill, or of scientific knowledge (skill if it concerns what merely comes to be, scientific knowledge if it concerns what is).
Thus these dispositions are neither innate in a determinate form, nor on the other hand do they arise from other higher states of knowledge, but they come about from sense-perception. It happens just as in battle when there is a rout: if one man stands fast, another does, and then another, until a position of strength is reached. The mind is so constituted as to be capable of this.
Let us now restate the account we have just given, which was not very clear. When one of the undifferentiated particular things ‘stands fast’, a primitive universal is in the mind; for although what one perceives is the particular thing, the perception is of a universal – for example of a man, not of Callias, the particular individual. Again, a stand is made in these primitive universals, and the process continues until the ultimate universal concepts stand (for example, such and such a species of animal is a step towards the general kind animal, and so on). So clearly it is [not by deduction but] by induction that we have to get to know the starting-points.
Concerning the intellectual faculties by which we reach the truth, some are always true, while others, such as opinion and reasoning, admit of falsehood; scientific knowledge and intuition (nous) are always true. No other kind of thought except intuition is more accurate than scientific knowledge, and the starting-points are more knowable than the demonstrations which proceed from them … Hence there cannot be scientific knowledge of the starting-points; and since nothing can be more true than scientific knowledge except intuition, it is intuition that grasps the starting-points.
Specimen Questions
1 What does Aristotle mean by ‘demonstrative knowledge’? How does he think we grasp the starting points for such knowledge?
2 Aristotle thinks of the senses as innate capacities that deliver information to us. How does knowledge based on sense-perception develop?
3 Explain how Aristotle thinks we can reach an understanding of universals on the basis of sense-perception.
Suggestions for Further Reading (Including Internet Resources)
1 Aristotle, Posterior Analytics. There is a version of the complete text translated and edited by J. Barnes (Oxford: Clarendon, 1975).
2 An excellent introduction to Aristotle’s thought, including numerous extracts from key texts, is J. L. Ackrill, Aristotle the Philosopher (Oxford: Oxford University Press, 1981).
3 See also D. J. Allen, The Philosophy of Aristotle (Oxford: Oxford University Press, 1952); J. Barnes, Aristotle (Oxford: Oxford University Press, 1982); W. D. Ross, Aristotle (London: Methuen, 1949).
4 For a more detailed study of Aristotle’s views on knowledge, see C. C. W. Taylor, ‘Aristotle’s Epistemology’, in S. Everson (ed.), Epistemology (Cambridge: Cambridge University Press, 1990).
5 See also J. Barnes, M. Schofield and R. Sorabji, (eds.), Articles on Aristotle (London: Duckworth, 1975–9), vols 1 and 4; J. Barnes (ed.), The Cambridge Companion to Aristotle (Cambridge: Cambridge University Press, 1995).
6 An excellent study of Aristotle’s account of sensory perception can be found in A. Marmodoro, Aristotle on Perceiving Objects (Oxford: Oxford University Press, 2014).
7 For Plato’s potential influence on this part of the Posterior Analytics see P. Adamson, ‘Posterior Analytics II.19: A Dialogue with Plato’, in Bul letin of the Institute of Classical Studies, Suppl. 107: 1–19 (Wiley Online Library, 2015).
8 See also P. Adamson’s podcast at https://historyofphilosophy.net/aristotle-epistemology, on Aristotle’s Posterior Analytics, ‘A Principled Stand: Aristotle’s Epistemology’ (Episode 36).
9 Two reliable internet resources with entries on Aristotle’s logic are the Stanford Encyclopedia of Philosophy at https://plato.stanford.edu/entries/aristotle-logic/#AriSci (by R. Smith), and the Internet Encyclopedia of Philosophy at https://www.iep.utm.edu/aris-log/ (by L. F. Groarke).
Notes
* Aristotle, Posterior Analytics [Analytica Hystera, c.330 BC], extracts from Bk I, ch. 1 (71a1–4), ch. 2 (71b9–25), ch. 4 (73a21–5), ch. 8 (75b21–36); Bk II, ch. 19 (99b20–110b12). Translation by John Cottingham.
1 1 Compare the first sentence of this extract.
2 2 A (rational) account or general concept.
4 New Foundations for Knowledge: René Descartes, Meditations*
Both in Plato’s search for eternal, unchanging objects of knowledge, and in Aristotle’s definition of true knowledge as being of that which cannot be otherwise, we can see the idea that what qualifies as knowledge must have a certain stability. Many centuries later, at the start of what is known as the ‘early modern’ period, this theme was taken up, though in a very different way, by René Descartes, whose writings had a profound effect on the subsequent development of philosophy in general and epistemology in particular.
Descartes became struck by the instability and unreliability of many of the accepted doctrines he had been taught as a student. In his Discourse on the Method (Discours de la méthode) published anonymously in 1637, he remarked of the philosophy he had learnt at school that despite having been taught for many centuries, it contained ‘no point that was not disputed and hence doubtful’. And as for other sciences, in so far as they borrowed their principles from philosophy, ‘nothing solid could be built on such shaky foundations’. In his masterpiece, the Meditations on First Philosophy, published in Latin in 1641, Descartes records his determination to sweep away all previously accepted opinions, and start afresh. His project is nothing less than the reconstruction of knowledge from the foundations upwards. To pursue this goal, he devises a systematic method of doubt: anything that can be called into question, for any reason whatever, will be discarded. Previous beliefs acquired via the senses are all jettisoned, on the grounds that the senses have sometimes