It must not be assumed that people who are brilliant in their work, rational in their thinking, caring in their attitude and sympathetic to others in their daily life are necessarily acting “out of character” when confronted with strong desires.
There are situations, and powerful sexual desire is almost certainly one of them, when a person is no longer in control of his or her actions. I say “almost certainly” for I have not seen the results of any experiments on this topic. But there have been papers on the cerebral activity that accompanies intense feelings of love as well as sexual activity. These have shown that, in addition to cortical areas that are active during these experiences, the two states, and especially the latter, lead to de-activation of large parts of the cortex.
Included in the de-activated areas are those which are traditionally thought to be important for judgment. Hence, this cortical de-activation may provide the reason for why we “take leave of our senses” in these conditions and sometimes behave in ways which are injurious to ourselves and others, as well as being incomprehensible and “out of character”.
One consequence is that we are less judgmental about those we love; another consequence is that we are also less judgmental about ourselves, our actions and even our future. Put more briefly, the first and highest priority is satisfy the desire.
How else to account for why great and honourable men and women have risked their future in trying to satisfy their desire, often through behaviour that is incomprehensible and “out of character”?
It is also important to note, as a reflection of brain specializations, that this lapse in judgment is not universal. One who takes "leaves of his senses" in matters of love or desire may be quite rational in judgment of mathematical or historical or scientific problems. In other words, it is not the faculty of judgment that is lost but only judgment in certain domains.
Whenever the world is mesmerized by the downfall of one man through a momentary lapse of judgment, we might do well to recall that in situations of love and desire, we may not be in control of our actions, or be in only minimal control of our actions because of the de-activation of our cortex. Consequently, we should not be too quick to pass a moral judgment.