Principles of Philosophy
162 quotes
Biography
"[T]he word philosophy signifies the study of wisdom... [i.e.,] not merely prudence in the management of affairs, but a perfect knowledge of all... man can know... for... conduct... health and... discovery of all... arts, and that knowledge to subserve these ends must... be deduced from first causes...[i.e.,] Principles."
"God is... the only being... absolutely wise... who possesses a perfect knowledge of all things; but... men are more or less wise as their knowledge of the most important truths is greater or less."
"[T]o live without philosophising is... the same as keeping the eyes closed..."
"[M]en, of whom the chief part is the mind, ought to make the search after wisdom their principal care, for wisdom is the true nourishment... [M]any... would not fail in the search, if they would but hope for success... and knew the degree of their capabilities..."
"There is no mind... which remains so firmly bound up in the objects of the senses, as not sometime... to turn... away from them in the aspiration after... higher good, although not knowing... wherein that good consists."
"The greatest favourites of fortune—those who have health, honours, and riches in abundance—are not more exempt from [these] aspirations... nay... [T]hese are the persons who sigh... most deeply after another good greater and more perfect... But the supreme good, considered by natural reason without the light of faith, is... knowledge of truth through its first causes... [i.e.,] the wisdom of which philosophy is the study. ...[A]ll that is required to gain assent to their truth is that they be well stated."
"[T]hey who make pretensions to philosophy are often less wise and reasonable than others who never applied themselves..."
"The first degree contains only notions so clear... that they can be acquired without meditation; the second comprehends all that the experience of the senses dictates; the third, that which the conversation of other men teaches us; ...the fourth, the reading, ...especially of such ...written by persons capable of ...proper instruction ...[A]ll the wisdom we in ordinary possess is acquired... in these... ways; for I do not class divine revelation among them, because it does not conduct us by degrees, but elevates us at once to an infallible faith."
"There have been... in all ages great minds who endeavoured to find a fifth road... more sure and elevated... The path they essayed was the search of first causes and true principles, from which might be deduced the reasons of all that can be known... [T]o them the appellation of philosophers has been... accorded."
"I am not aware that... any one of them... has succeeded.... The first and chief... are Plato and Aristotle, between whom there was no difference, except that the former, following... his master, Socrates, ingenuously confessed that he had never yet been able to find anything certain... contented to write what seemed... probable, imagining... principles by which he endeavoured to account for the other things."
"Aristotle... characterised by less candour, although... twenty years the disciple of Plato, and with no principles beyond... his master, completely reversed his mode... and proposed as true and certain what... he... never esteemed as such. But these two... acquired much judgment and wisdom by the four preceding means... which raised their authority... high, so much... that those who succeeded them were willing... to acquiesce in their opinions, [rather] than to seek... for themselves. The chief question among their disciples... whether we ought... doubt... all things or hold some as certain,—a dispute which led... into extravagant errors; for a part of those... for doubt, extended it... to the neglect of... ordinary rules... [of] conduct; those... who maintained the doctrine of certainty, supposing that it must depend upon the senses, trusted entirely to them. To such an extent was this carried by Epicurus, that... he... affirm[ed], contrary to all the reasonings of the astronomers, that the sun is no larger than it appears."
"[W]hile we only possess... knowledge... acquired in the... four grades of wisdom, we ought not to doubt... things that appear... true in... the conduct of life, nor esteem them as so certain that we cannot change our opinions.., even though constrained by... reason."
"From ignorance of this truth, or... from neglect of it, the majority of those who... aspired to be philosophers, blindly followed Aristotle, so... frequently corrupted... his writings, and attributed... opinions... he would not recognise... and those who did not follow him, among whom are... many of the greatest minds, did yet not escape... his opinions in their youth... the staple... in the schools; and thus... they could not rise to the knowledge of true principles."
"[T]he philosophers... all laid down as a principle what they did not perfectly know. ...I know none of them who did not suppose that there was gravity in terrestrial bodies; but although experience shows us... [heavy] bodies... descend towards the centre of the earth, we do not... know the nature of gravity... [i.e.,] the cause or principle in virtue of which bodies descend, and we must derive our knowledge of it from some other source."
"The same may be said of a vacuum and atoms, of heat and cold, of dryness and humidity, and of salt, sulphur, and mercury, and the other things... some... adopted as... principles."
"[N]o conclusion deduced from a principle which is not clear can be evident, even although the deduction be formally valid; and hence... no reasonings based on such principles could lead... to the certain knowledge... nor... advance them... in the search after wisdom."
"And if they did discover any truth, this was due to one or other of the four means above..."
"[J]ust as in travelling, when we turn our back upon the place to which we were going, we recede the farther from it in proportion as we proceed in the new direction for a greater length of time and with greater speed, so that, though we may be afterwards brought back to the right way, we cannot nevertheless arrive at the destined place as soon as if we had not moved backwards at all..."
"[S]o in philosophy, when we make use of false principles, we depart the farther from the knowledge of truth and wisdom... in proportion to the care with which we cultivate them, and apply ourselves to the deduction of diverse consequences from them, thinking that we are philosophising well, while we are only departing the farther from the truth; from which it must be inferred that they who have learned the least of all that has been hitherto distinguished by the name of philosophy are the most fitted for the apprehension of truth."
"[T]he grounds for holding that the true principles by which we may reach that highest... wisdom wherein consists the sovereign good of human life, are those I have proposed in this work..."
"[T]wo considerations... are sufficient... first... that these principles are... clear, and... second, that we can deduce all other truths from them; for it is only these two conditions that are required in true principles."
"But I easily prove that they are very clear; firstly, by a reference to the manner in which I found them, namely, by rejecting all propositions that were... doubtful, for it is certain that such as could not be rejected... are the most evident and clear which the human mind can know. Thus by considering that he who strives to doubt of all is unable nevertheless to doubt that he is while he doubts, and that what reasons thus, in not being able to doubt of itself and doubting nevertheless of everything else, is not that which we call our body, but... our mind or thought."
"I have taken... for the first principle, from which I... deduced the following truths... that there is a God who is the author of all... and... being the source of all truth, cannot have created our understanding... as to be deceived in... judgments... of the things of which it possesses... clear and distinct perception."
"Those are all the principles of which I avail myself touching immaterial or metaphysical objects, from which I most clearly deduce these other principles of physical or corporeal things, namely, that there are bodies extended in length, breadth, and depth, which are of diverse figures and are moved in a variety of ways."
"Such are in sum the principles from which I deduce all other truths."