9. THESE are the chief branches of those obstructions to knowledge, which this author has reduced under his first head of false conceptions. The second head contains the errors, to which particular persons are more especially obnoxious[17]. One of these is the consequence of a preceding observation: that as we are exposed to be captivated by any opinions, which have once taken possession of our minds; so in particular, natural knowledge has been much corrupted by the strong attachment of men to some one part of science, of which they reputed themselves the inventers, or about which they have spent much of their time; and hence have been apt to conceive it to be of greater use in the study of natural philosophy than it was: like ARISTOTLE, who reduced his physics to logical disputations; and the chymists, who thought, that nature could be laid open only by the force of their fires[18]. Some again are wholly carried away by an excessive veneration for antiquity; others, by too great fondness for the moderns; few having their minds so well balanced, as neither to depreciate the merit of the ancients, nor yet to despise the real improvements of later times[19]. To this is added by his Lordship a difference in the genius of men, that some are most fitted to observe the similitude, there is in things, while others are more qualified to discern the particulars, wherein they disagree; both which dispositions of mind are useful: but to the prejudice of philosophy men are apt to run into excess in each; while one sort of genius dwells too much upon the gross and sum of things, and the other upon trifling minutenesses and shadowy distinctions[20]. 10. UNDER the third head of prejudices and false notions this writer considers such, as follow from the lax and indefinite use of words in ordinary discourse; which occasions great ambiguities and uncertainties in philosophical debates (as another eminent philosopher has since shewn more at large[21];) insomuch that this our author thinks a strict defining of terms to be scarce an infallible remedy against this inconvenience[22]. And perhaps he has no small reason on his side: for the common inaccurate sense of words, notwithstanding the limitations given them by definitions, will offer it self so constantly to the mind, as to require great caution and circumspection for us not to be deceived thereby. Of this we have a very eminent instance in the great disputes, that have been raised about the use of the word attraction in philosophy; of which we shall be obliged hereafter to make particular mention[23]. Words thus to be guarded against are of two kinds. Some are names of things, that are only imaginary[24]; such words are wholly to be rejected. But there are other terms, that allude to what is real, though their signification is confused[25]. And these latter must of necessity be continued in use; but their sense cleared up, and freed, as much as possible, from obscurity.