Chapter XXVII: Madam,

You are pleased to honor me so far, that you do not onely spend some time in the perusing of my Book called _Philosophical Opinions_, but take it so much into your consideration, as to examine every opinion of mine which dissents from the common way of the Schools, marking those places which seem somewhat obscure, and desiring my explanation of them; All which, I do not onely acknowledg as a great favour, but as an infallible testimony of your true and unfeigned friendship; and I cannot chuse but publish it to all the world; both for the honour of your self, as to let every body know the part of so true a friend, who is so much concerned for the honour and benefit of my poor Works; as also for the good of my mentioned Book, which by this means will be rendred more intelligible; for I must confess that my Philosophical Opinions are not so plain and perspicuous as to be perfectly understood at the first reading, which I am sorry for. And there be two chief reasons why they are so: First, Because they are new, and never vented before; for the have their original meerly from my own conceptions, and are not taken out of other Philosophers. Next, because I being a Woman, and not bred up to Scholarship, did want names and terms of Art, and therefore being not versed in the Writings of other Philosophers, but what I knew by hearing, I could not form my named Book so methodically, and express my opinions so artificially and clearly, as I might have done, had I been studious in the reading of Philosophical Books, or bred a Scholar; for then I might have dressed them with a fine coloured Covering of Logick and Geometry, and set them out in a handsome array; by which I might have also cover'd my ignorance, like as Stage-Players do cover their mean persons or degrees with fine Cloathes. But, as I said, I being void of Learning and Art, did put them forth according to my own conceptions, and as I did understand them myself; but since I have hitherto by the reading of those famous and learned _Authors_ you sent me, attained to the knowledg of some artificial Terms, I shall not spare any labour and pains to make my opinions so intelligible, that every one, who without partiality, spleen, or malice, doth read them, may also easily understand them: And thus I shall likewise endeavour to give such answers to your scruples, objections, or questions, as may explain those passages which seem obscure, and satisfie your desire. In the first place, and in general, you desire to know, _Whether any truth may be had in Natural Philosophy_: for since all this study is grounded upon probability, and he that thinks he has the most probable reasons for his opinion, may be as far off from truth, as he who is thought to have the least; nay, what seems most probable to day, may seem least probable to morrow, especially if an ingenious opposer, bring rational arguments against it: Therefore you think it is but vain for any one to trouble his brain with searching and enquiring after such things wherein neither truth nor certainty can be had. To which, I answer: That the undoubted truth in Natural Philosophy, is, in my opinion, like the Philosopher's Stone in Chymistry, which has been sought for by many learned and ingenious Persons, and will be sought as long as the Art of Chymistry doth last; but although they cannot find the Philosophers Stone, yet by the help of this Art they have found out many rare things both for use and knowledg. The like in Natural Philosophy, although Natural Philosophers cannot find out the absolute truth of Nature, or Natures ground-works, or the hidden causes of natural effects; nevertheless they have found out many necessary and profitable Arts and Sciences, to benefit the life of man; for without Natural Philosophy we should have lived in dark ignorance, not knowing the motions of the Heavens, the cause of the Eclipses, the influences of the Stars, the use of Numbers, Measures, and Weights, the vertues and effects of Vegetables and Minerals, the Art of Architecture, Navigation, and the like: Indeed all Arts and Sciences do adscribe their original to the study of Natural Philosophy; and those men are both unwise and ungrateful, that will refuse rich gifts because they cannot be masters of all Wealth; and they are fools, that will not take remedies when they are sick, because Medicines can onely recover them from death for a time, but not make them live for ever. But to conclude, Probability is next to truth, and the search of a hidden cause finds out visible effects; and this truth do natural Philosophers find, that there are more fools, then wise men, which fools will never attain to the honour of being Natural Philosophers. And thus leaving them, I rest,

Madam,

_Your Ladiships_

_humble and faithful Servant._