Reasoning, as the highest type of thinking, includes all that thinking in general does, and adds some particular requirement which differentiates it from the simpler forms. Further discussion of it, then, should make clearer the essential in thinking as a process, as well as make clear its most difficult form. Reasoning is defined by Miller as "controlled thinking,--thinking organized and systematized according to laws and principles and carried on by use of superior technique."[9] Reasoning, then, is the kind of thinking that deals directly with laws and principles. Much thinking may be carried on without any overt, definite use of laws and principles, as in constructive imagination or in apperception, but, if this is so, it seems better to call the thinking by one of the other names. Of course this classification is somewhat arbitrary, but there can be no question that types of thinking do differ. As has already been noted, some psychologists have used the terms thinking and reasoning as synonyms, but such usage has resulted in confusion and has not been of practical value. It is only as the mental process desired becomes clearly conceived of, its connotations and denotation clearly defined, that it becomes a real goal towards Which a teacher or learner may strive. This, then, is the primary criterion of reasoning--that the thinker be dealing consciously with laws and principles. An acceptance of this first essential makes clear that the particular process of reasoning cannot be carried on in subjects which lack laws and principles. Spelling, elementary reading, vocabulary study, most of the early work in music and art, the acquisition of facts wherever found--these situations may offer opportunity for thinking, but little if any for reasoning. Because a teacher is using the development method does not mean necessarily that her students are reasoning. The two terms are not in any way synonymous. The second essential in reasoning is the presence of a definite technique. This technique consists of two factors: first, certain definite mental states, and second, the use of the process of thinking by either the inductive or the deductive method.