Gentlemen of the Jury, can you dispute the truth of the passage I have quoted from Dr. Whitby? Will you, by your verdict, pronounce it to be "_a crime_ not to perform _impossibilities_, and endeavour to _force us to believe_ what does not appear to us to be true?" Gentlemen, you cannot do it. Let us briefly trace the operations of the human mind, and we shall find that the mind is governed by a law of necessity. Are we not definitely and necessarily’ affected by the circumstances which surround us? Have we power to avoid receiving impressions from the objects presented to us? If we have not, which is now universally admitted by intelligent men, then the act of _perceiving_, or _forming ideas_, is a necessary mental operation. Can we, for instance, have an idea of a man when a monkey is presented to us? Or of colours other than those which are placed before our visual organs? We cannot, if the eye be not diseased, perceive red to be green, or green red. The power of _perception_, therefore, appears to be perfectly involuntary--it is governed by a law of necessity. The next operation of the mind is to form a judgment of the things perceived; and it is these two things--_perceiving_ and _judging_--which constitute a man’s knowledge or experience. If two bodies of different magnitudes are presented to our view, are we not compelled to judge of them according to the impression they respectively make upon the mind? It is precisely the same with _men, manners, and opinions_. Must we not conclude that things are what they appear to be, till we know the contrary? I would appeal to your own experience, Gentlemen, whether you do not invariably and necessarily judge of men and things according to their inherent or imaginary qualities? Some men, indeed, are puzzled to account for the diversity of judgment observable where different men examine the same subject, and from the same data; but this circumstance is easily accounted for. It results simply from this fact, that men judge of things precisely as they appear to them: and the different judgments formed of the same things are ascribable wholly to the different degrees of strength in the power of perception, and to the extent and variety of knowledge previously acquired. _Perception and judgment_, therefore, appear to be involuntary and necessary. Gentlemen, if this be true, is a man who has arrived at conclusions adverse to the _received opinions_ of society a fit subject of punishment? If not, how much less so is the bookseller who merely sells his book?