Classicly

A Candid Examination of Theism is an essay on theism written by George John Romanes, a Canadian-Scots evolutionary biologist and physiologist who laid the foundation of what he called comparative psychology, postulating a similarity of cognitive processes and mechanisms between humans and other animals.

Author's Preface:

The following essay was written several years ago; but I have hitherto refrained from publishing it, lest, after having done so, I should find that more mature thought had modified the conclusions which the essay sets forth. Judging, however, that it is now more than ever improbable that I shall myself be able to detect any errors in my reasoning, I feel that it is time to present the latter to the contemplation of other minds; and in doing so, I make this explanation only because I feel it desirable to state at the outset that the present treatise was written before the publication of Mr. Mill's treatise on the same subject.