 Theory number two, it is language is essential for thought. According to this theory, we must learn language how to produce or understand speech, otherwise we cannot develop thinking. So this theory highlights the importance of language, understanding of language with regard to its rules and vocabulary and how it is important that in order to understand and produce speech, we must know what language is and what it is comprising of. Proponents of this theory basically believe number one, the language system with its rule of vocabulary is necessary for thought. So rules are very important in terms of the kind of sentences you are using, is a past tense, present tense, future tense and the type of vocabulary that you are using. So the rules of the language as well as the vocabulary which is very important and which actually constitutes to the overall system of language. Thought was derived from speech production and thought is supposed to be language specific and not universal. Now this means that thought has to rely completely on the rules and vocabulary of a language. So it is language specific and it cannot be considered as a general or very universal process which is similar among all humans. Since we know that people have different point of view, different people speak different languages and through these languages they reflect their own specific world view. So therefore language specific thoughts are the one which has been highlighted here and it is according to this theory there is no such thing as the universal specificity as far as the languages are concerned. Now the inner request of this theory number one which says deaf persons without language can think. Now if one holds that language is the basis for thought then these deaf children do not think and that they were merely robots. Another point is multilinguals who are whole persons. The belief that multilingual are specially people having the multiple linguistic knowledge and which makes their personality kind of split into different languages is something that has been discussed here. According to this multilingual are whole persons. Now according to this theory if multilinguals have more than one thought process, one from each language each person would not be able to think coherently. So that is person who is having the multilingual aspect of multilingual process of thought would be a person who would not be able to think coherently or would have separate thought, intelligence, personalities, etc. Persons knowing three languages would have formed three systems of thought. For example this is what the idea behind multilingual as whole person is that people having different language systems will have different systems of thought. Now this is not true because it is proved through a case that a multilingual and a monolingual child living in a same environment have no difference in terms of beliefs, values, personality and their perceptions of the world and nature. Number three which says intelligent animal behaviors occurs without language. Thought must have some basis other than language. Now the following example can prove this. For example monkeys without language can develop some simple counting and arithmetic abilities. Then we have insects. Insects also without language can think of strategies of gathering food, defending themselves and finding mates. Since animals can think without language there is no reason to believe that humans cannot do the same. So we have the conflicting views with regard to this and the inadequacies of the theory are related to deaf persons ability to think and the ability of multilingual as being whole persons and also the intelligent animal behavior which can occur without language. So according to this theory we must learn language how to produce understand language otherwise we cannot develop thinking.