A scientific fact is supposed to be entitled to credence, when accompanied by proper scientific proof; but, nevertheless, many worthy people cannot resist the conclusion, that, if a man's moral character is determined by the quality of the brain, then there is no such thing as responsibility. And so we are brought up all standing against the old problem of moral liberty, on which oceans of ink have been shed to little purpose. Heaven forbid that we should add another drop! for our object will be served by stating very briefly the scientific view of this phenomenon. Every creature is free, within the limits of the constitution which Nature has given him, to act and to think, each after his kind. The horse rejoices in the liberty of acting like a horse, and not like an ox; and man enjoys the privilege of acting the part of a man, and not of a disembodied spirit. If the limbs of the former are struck by an atrophy, we do not expect him to win the race. If the brain of the latter is blasted by disease or deterioration, we cannot expect the fruits of a sound and vigorous organism. When we say that a person with a brain vitiated by an accumulation of hereditary defects is incapable of that degree of moral excellence which is manifested by men of the soundest brains, we utter a truism as self-evident, apparently, as when we say that the ox is incapable of the fleetness of the horse or the ferocity of the tiger. It is immaterial whether the cerebral condition in question is one of original constitution or of acquired deficiency, because the relation between the physical and the moral must be the same in the one case as in the other. In the toiling masses, who, from childhood, are brought face to face with want and vice, we do not expect to find the moral graces of a Channing or a Cheverus; and we do not hold them to a very strict responsibility for the deficiency. But they are not utterly destitute of a moral sense, and what we have a right to expect is, that they improve, in a reasonable degree, the light and opportunities which have fallen to their lot. The principle is precisely the same as it regards those whose brains have been vitiated by some noxious agency. To make them morally responsible in an equal degree with men more happily endowed would be repugnant to every idea of right and justice. But within the range of their capacity, whatever it may be, they are free, and accountable for the use of their liberty. True, there is often difficulty in making these distinctions, even where the necessity for it is the greatest; but we dissent from the conclusion, that therefore the doctrine can have but little practical value. It is something to have the fact of the intimate connection between organic conditions and moral manifestations distinctly recognized. The advance of knowledge will be steadily widening the practical application of the fact. A judge might not be justified in favoring the acquittal of a criminal on the ground of his having