– 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 proved unreliable. Even such straightforward beliefs as ‘I am now sitting by the fire’ are doubted, on the grounds that I might be dreaming; and the argument is then broadened to question whether I can know for certain that anything external to the mind really exists. The argument next turns to the abstract propositions of mathematics, which seem to be immune from the previous doubts since their truth does not depend on whether their objects actually exist; but even these are called into question by the thought that an all-powerful God might make me go wrong ‘every time I add two and three’. To reinforce all the doubts, an imaginary scenario is introduced of a ‘malicious demon of the utmost power who employs all his energies to deceive me’. Finally, at the start of the Second Meditation, the meditator reaches his ‘Archimedian point’. No matter how much he is deceived, there is one truth that cannot be doubted: ‘I am, I exist, is certain, every time it is conceived in the mind.’ This, elsewhere expressed in the famous formula ‘I am thinking therefore I exist’ (in French, je pense donc je suis, or, in Latin, cogito ergo sum), is the first principle of Descartes’s new philosophy.
What can be called into doubt
Some years ago I was struck by the large number of falsehoods that I had accepted as true in my childhood, and by the highly doubtful nature of the whole edifice that I had subsequently based on them. I realized that it was necessary, once in the course of my life, to demolish everything completely and start again right from the foundations if I wanted to establish anything at all in the sciences that was stable and likely to last. But the task looked an enormous one, and I began to wait until I should reach a mature enough age to ensure that no subsequent time of life would be more suitable for tackling such inquiries. This led me to put the project off for so long that I would now be to blame if by pondering over it any further I wasted the time still left for carrying it out. So today I have expressly rid my mind of all worries and arranged
