We begin by distinguishing among thoughts, words, and deeds. I will assume that most deeds and some words are justifiably morally evaluable, justifiably evaluable as either morally right or morally wrong. The question I want to raise is whether mere thoughts (thoughts that do not actually spill over into words or actions, though they possess the potential to do so) are justifiably morally evaluable. In a comment, I wrote:
With respect to Matthew 5.27-28, a married man who has a sexual outlet, but who yet entertains (with hospitality) the thought of having sex with another woman is lustful in a morally objectionable way even though he does not act on his desire and is no lecher.
The scenario is this. You have a married man who is sexually capable and vigorous and whose wife is ready, willing, and able to oblige him in matters sexual. In this sense, he has a 'sexual outlet.' But like almost all heterosexual men, he has recurrent thoughts of sexual intercourse with a wide variety of other women. (I hope my distaff readers, all three of them, are not unduly shocked by this obvious truth.) Now suppose we agree that it is morally wrong for such a man to have sexual relations with a woman not his wife, and also that it is morally wrong for him to propose such a thing to a woman not his wife. And let us also agree that there is nothing morally wrong with the mere transient occurrence of these thoughts of sex with 'extramural' women, and that it is indeed quite natural that these thoughts occur from time to time (though not continuously or obsessively) especially if the man is a sexually capable resident of a sex-saturated society such as the U. S. of A.
Given all of these assumptions, my question is: Is it morally wrong for such a man to dwell on and mentally elaborate such sexual thoughts even while firmly resolving never to act upon them? By 'dwell on and mentally elaborate' I mean the opposite of 'note the thought's occurrence but then dismiss it.' Although I am employing a sexual example, I mean to pose my question in full generality: Are some mere thoughts of morally wrong actions, no matter the nature of the moral wrong, themselves morally wrong? The thoughts might be sexual, murderous, larcenous, you name it.
My answer is yes. One ought not dwell on such mere thoughts and one ought to dismiss them. If this is right, then a mere thought can be morally wrong. A correspondent responds as follows:
We aren't telepaths, so my thinking, if I keep my damned mouth shut, is not accessible to others, and so has no effect on them, for good or ill. I see no grounds for claiming that mere thinking is morally objectionable if it has no effect on others.
To be sure, this kind of thinking is probably not good for my state of mind and mental health. A grown man should have better things to do than indulge in teenage fantasies. But I just don't get the idea that it is MORALLY wrong or objectionable. You obviously have some perspective on this issue that I am missing. Maybe vice has caused more damage to my moral faculties than I know. Alcohol isn't good for them either.
I can think of four arguments for my thesis that some mere thoughts are morally objectionable. I grant arguendo for the space of this post that telepathic influence does not occur. If, to use some '60s jargon, our negative thoughts send out 'bad vibes' that can influence and harm others, then of course some mere thoughts are justifiably morally evaluable.
1. The first is the argument from the potentiality of thoughts to translate themselves into words and deeds. Although a murderous (adulterous, etc.) thought need not eventuate in a murderous (adulterous, etc.) deed, the entertaining (with hospitality, if you catch my drift) of such thoughts raises the probability of the thinker of the thought's becoming an agent of the corresponding action. I am assuming arguendo that these thoughts do no actual harm to anyone other than the one who harbors them. Still, if the deed is morally wrong, and the (non- jocose) verbal threat of the deed is morally wrong, then it is difficult to see why the rehearsal and mental elaboration of the deed in thought should not also be considered morally wrong given the fact that such rehearsal and elaboration raise the probability of an enactment.
If you maintain that murderous thoughts, if they are mere thoughts, are not morally blameworthy but morally neutral since they remain within the mind of their thinker, then by parity of reasoning you should also maintain that kind thoughts, if they are mere thoughts, no matter how protracted or developed, should not be regarded as morally praiseworthy but as morally neutral since they too remain within the mind of their thinker. But this is morally counterintuitive. We tend to regard the kind-hearted person, even when he is not speaking or acting out his kind-heartedness, as morally valuable and worthy of commendation, simply because he is disposed to speak and act in ways that are kind. Therefore, we ought to regard what are called evil thoughts as themselves evil whether or not they eventuate in evil words or thoughts.
There is also this ordinary language consideration. We do call certain mere thoughts evil. Thus we apply 'evil' not only to the act of killing a baby for fun but also to the mere thought of killing a baby for fun. Is this mere equivocation as in the case of 'bank' in 'money bank' and 'river bank'? Obviously not. It is more like the analogical use of 'unhealthy' in 'unhealthy diet' and 'unhealthy animal.' Although the thought is not as evil as the deed, the thought is evil in that its rehearsal raises the probability of the deed.
In short, thoughts are the seeds of words and deeds. If the words and deeds are justifiably morally evaluable, then so are the thoughts out of which they grow. The reader will appreciate that I am not claiming that the consequent of this conditional follows logically from the antecedent. I am simply asserting the conditional on the basis of the above considerations.
2. My correspondent and I agree that both murder and the (non-jocose) verbal threat of murder are morally objectionable. We also agree that murdering someone is morally worse than verbally threatening to murder him. Now if the verbal threat to murder is morally wrong even though it causes no actual physical harm to the person threatened, then presumably the reason to think the threat is wrong is that it causes mental harm. But it wouldn't cause mental harm if the threat were taken to be idle, i.e., not likely to be enacted. So part of what makes the threat harmful and thus morally objectionable is its potentiality to be enacted. But a similar potentiality lies in the murderous thought. So if one can see that the verbal threat to murder is morally wrong, then one should be able to see that the premeditation is also morally wrong.
3. A disposition can exist without being manifested, and indeed without ever being manifested. Thus an agent can be irascible even when he is not showing anger. A disposition such as irascibility can be manifest in three different ways: in physical actions (Hillary throws lamp at Bill), in speech acts (Hillary yells something nasty at Bill), in evil thoughts ("I'll kill the SOB!"). Now if it is our justifiable moral practice to evaluate dispositions -- and I'd say that it is -- and if dispositions are at the source of three different type of manifestation, and are therefore more fundamental than all three of their modes of manifestation, then a fortiori some mere thoughts are justifiably morally evaluable.
The three arguments just given are related but subtly different. Here is a very different one.
4. My correspondent writes, "I see no grounds for claiming that mere thinking is morally objectionable if it has no effect on others." But there is the possibility that the entertaining (with hospitality) of certain thoughts we call evil harms the thinker of the thoughts. So this gives us a fourth argument. The argument could be sketched as follows. One has duties toward oneself as Kant vigorously maintains. One such duty is the duty not to pollute one's own mind with negative thoughts, analogously as one has the duty not to pollute one's body with drugs and alcohol and bad food. The man who pollutes his mind with murderous, lecherous, larcenous, etc. thoughts violates a duty he has to himself. To violate any duty is to do something morally impermissible. Therefore, harboring murderous, lecherous, etc. thoughts is morally impermissible and thus morally objectionable.