Viewing page 489 of 504

This transcription has been completed. Contact us with corrections.

abstract, will therefore correct an error, which alone belongs to them, but no other; they are consequently limited within their own proper bounds of abstraction, and there is no such thing as practical geometry, algebra, and fluxions, but what is contained in and confined to the abstract; though we sometimes meet with them imposed upon the public in another sense.  
    Hence it appears that every thing in these sciences becomes known [[underline]] à priori [[/underline]] or is the production of the human mind by reason alone, without the knowledge and assistance of any effect from a prior cause.*  This way of reasoning [[underline]] à priori [[/underline]] will I believe be found peculiar to, and the distinguishing characteristic of all sciences, strictly so called, though it is unobserved [[all the writers I have met with, who reckon the seven liberal sciences, to be grammar, logic, oratory, arithmetic, geometry, astronomy and music; but I cannot subscribe to astronomy as such, because all our knowledge of it is not [[underline]] à priori [[/underline]] but [[underline] à posteriori [[/underline].
   On the contrary; In mechanics, astronomy, natural philosophy, and all the other arts; where the manner of operation is invisible and the physical cause of any effect does not fall under the cognizance of our senses, we have no ground, no standard, to reason [[underline]] à priori [[/underline]], as in the sciences; we can no more comprehend these invisible operations, or have any knowledge of physical causes, than a blind man can of colors, a deaf man of sound, or one who has lost the sense of smelling can judge of odorous effluvia: for the former are no more the object of our senses than the latter are of those who want the peculiar senses to discern these. We therefore, having no previous data, cannot discern in what particular manner or which way these causes operate, nor can we form any judgement of the causes themselves, but by their effects.  The method of proceeding therefore in these arts, can never be by induction.

*They lying thus open and free to the reason of every man, and at liberty to be embraced by all, have obtained the epithet of liberal, and are called the liberal sciences.