DR REID.

To

TO DR

SIR,

T would be ungrateful at least, and al

IT

most uncandid, were I to publish these Effays, without infcribing them to You; confcious as I am, that, but for the assistance which I have received from your writings, they never could have been composed, nor thought of; and that, but for the approbation which many parts of them have met with from you, they never would have been published. Indeed the hint of the principal argument which I have endeavoured to ftate and illustrate in the first of thefe Effays, the only one contained in this volume, was taken from an obfervation of yours, in one of your Effays on

the intellectual Powers of Man; the profecution and application of which observation, I find, had not occurred to yourfelf.

I do not, however, presume to publish my fpeculations as wholly approved of by you; nor to make you in any degree anfwerable for fuch parts of them as may be thought erroneous or doubtful. If they cannot answer for themselves, it is I alone that must answer for them.

I have obferved with much anxiety, that fome of my obfervations and reasonings, which to myself appeared just and important, have not appeared fo to you; and, in confequence of this diftruft or diffent on your part, I have been led to examine with peculiar care, and to illustrate very fully, all those fufpected parts of my difquifitions. The refult of this more rigorous examination, in most instances, has

been,

been, to confirm the opinion which I had formed before; and to enable me to illuftrate it better, and to anfwer, in a manner which I think fatisfactory, the principal objections that you had urged against my speculations.

The difference of opinion between us, has, I think, been chiefly on certain points, which, from the nature of my inquiries, I have had occafion to examine very minutely; much more fo, I believe, than had ever been done before; and of which, though they had not altogether escaped your attention, you had taken only a more remote and general view. It is not for me, but for others, to judge, whether my attention to these points in fcience has been fuccefsfully employed or

not.

I am too well acquainted with you, and with your candour in all matters of sci

pre

ence, to fuppofe that any explanation or apology to you could be neceflary for my conduct in this refpect; or to think that you could have expected or wished for any other conduct on my part. It is for the fake of others, who might be ftruck with certain differences of opinion between us, and who might miftake them for an inconfiftency with refpect to thofe important principles about which we perfectly agree, that I think it expedient to give some liminary explanation and juftification of my conduct. This I think I cannot better do than in the very words of BACON, whofe fentiments I am fure you know, and revere, as much as I do: Etfi non difpliceat regula, OPORTET DISCENTEM CREDERE; huic tamen conjungendum eft, OPORTET JAM EDOCTUM JUDICIO SUO UTI; difcipuli enim debent magiftris temporariam folum fidem, judicique fufpenfionem, donec penitus imbiberint artes; non autem ple

nam