Thought proper is where the power of the will is directing the activity of the mind. This explains the words "thoughtful", "thoughtless." The thoughtful person is one whose will directs his mind - whether he is doing a thing, or speaking, or thinking. So people call him a thinker. But the one who does not control his action, speech, and his thoughts by his will is thoughtless. So his thought is really imagination; his speech does not make sense, his actions become thoughtless or inconsiderate. In brief, these three things - thought, speech, and action - reveal the character of the thought. If they are controlled by the will, they show thoughtfulness; but if not so controlled, they are thoughtless, the person is called thoughtless.