for thoughts are only criminal, when they are first chosen, and then voluntarily continued.
Evil into the mind of God or man
May come and go, so unapprov'd, and leave
No spot or stain behind.Milton.
In futurity chiefly are the snares lodged, by which the imagination is entangled. Futurity is the proper abode of hope and fear, with all their train and progeny of subordinate apprehensions and desires. In futurity events and chances are yet floating at large, without apparent connexion with their causes, and we therefore easily indulge the liberty of gratifying ourselves with a pleasing choice. To pick and cull among possible advantages is, as the civil law terms it, in vacuum venire, to take what belongs to nobody; but it has this hazard in it, that we shall be unwilling to quit what we have seized, though an owner should be found. It is easy to think on that which may be gained, till at last we resolve to gain it, and to image the happiness of particular conditions till we can be easy in no other. We ought, at least, to let our desires fix upon nothing in another's power for the sake of our quiet, or in another's possession for the sake of our innocence. When a man finds himself led, though by a train of honest sentiments, to wish for that to which he has no right, he should start back as from a pitfall covered with flowers. He that fancies he should benefit the publick more in a great station than the man that fills it, will in time imagine it an act of virtue to supplant him; and as opposition readily kindles into hatred, his eagerness to do that good to which he is not called, will betray him to crimes, which in his original scheme were never proposed.