As soon as this has been carried to the utmost, you must further (that my experiment may be fairly tried) endeavour to throw yourself, in imagination, not only into the position, but also into the natural and acquired mental and moral perceptions of the person whose action you are taking into your consideration.  For this purpose you must often imagine—­natural dimness of perception, absence of acute sensibility, indifference to wounding the feelings of others from mere carelessness and want of reflective powers, little natural conscientiousness, an entire absence of the taste or the power of metaphysical examination into the effect produced by our actions.  All these natural deficiencies, you must further consider, may in this case be increased by a totally neglected education,—­first, by the want of parental discipline, and afterwards of that more important self-education which few people have sufficient strength of character to subject themselves to.  Lastly, I would have you consider especially the moral atmosphere in which they have habitually breathed:  according to the nature of this the mental health varies as certainly as the physical strength varies in a bracing or relaxing air.  A strong bodily constitution may resist longer, and finally be less affected by a deleterious atmosphere than a weak or diseased frame; and so it is with the mental constitution.  Minds insensibly imbibe the tone of the atmosphere in which they most frequently dwell; and though natural loftiness of character and natural conscientiousness may for a very long period resist such influences, it cannot be expected that inferior natures will be able to do so.

You are then to consider whether the habits of mind and conversation among those who are the constant associates of the persons you blame have been such as to cherish or to deaden keen and refined perceptions of moral excellence and nobility of mind; still further, whether their own literary tastes have created around them an even more penetrating atmosphere; whether from the elevated inspirations of appreciated poetry, from the truthful page of history, or from the stirring excitements of romantic fiction, their heart and their imagination have received those lofty lessons for which you judge them responsible, without knowing whether they have ever received them.

There is still another consideration.  While the actions of those who are not habitually under the control of high principle depend chiefly on the physical constitution, as they are too often a mere yielding to the immediate impulse of the senses, their judgment of men and things, on the contrary, when uninfluenced by personal feeling, depend probably more on that keen perception of the beautiful which is the natural instinct of a superior organization.  Morality and religion will indeed supply the place of these lofty natural instincts, by giving habits of mind which may in time become so burnt in, as it were, that they assume the form of natural instincts, while they are at once much safer guides and much stronger checks.