same instant choosing and taking one; which one is chosen and taken, most commonly, according as the parts of our bodies have been formed long since by our wills, or by other causes, to an habitual practice, or as those parts are determined by some particular circumstances at that time. And we may know, by reflection on our actions, that several of our choices have been determined to one among several objects by these last means, when no cause has arisen from the mere consideration of the objects themselves. For we know by experience that we either use all the parts of our bodies by habit, or according to some particular cause determining their use at that time.
Fourthly, there are in all trains of causes that precede their effects, and especially effects which nearly resemble each other, certain differences undiscernible on account of their minuteness and also on account of our not accustoming ourselves to attend to them, which yet, in concurrence with other causes, as necessarily produce their effect, as the last feather laid on breaks the horse’s back, and as a grain necessarily turns the balance between any weights, though the eye cannot discover which is the greatest weight or bulk by so small a difference. And I add, that as we know without such discovery by the eye, that if one scale rises and the other falls, there is a greater weight in one scale than the other, and also know that the least additional weight is sufficient to determine the scales, so likewise we may know that the least circumstance in the extensive chain of causes that precede every effect, is sufficient to produce an effect, and also know that there must be causes of our choice (though we do not, or cannot discern those causes) by knowing that every thing that has a beginning must have a cause. By which last principle we are as necessarily led to conceive a cause of action in man, where we see not the particular cause itself, as we are to conceive that a greater weight determines a scale, though our eyes discover no difference between the two weights.
