History presents many problems to the historian. Firstly, how does the historian know, that what he knows is true? Second, how can the historian certainly discover past events? And thirdly, how is the historian supposed to do research? All these questions can be answered only by a recourse to deduction.
First, what is deduction? Deduction is the method of reasoning opposed to the current mode of reasoning in history. More precisely, deduction is the type of reasoning wherein the truth values of the premises necessarily imply the truth value of the conclusion. This is opposed to the current inductive method of historiography. Now, the inductive method, is a type of reasoning where the truth value of the premises is related probabilistically to the conclusion. In the first mode, the evidential relations are ones of certainty, and in the second (inductive) mode, the evidential relations are ones of probability. So if your premises are true in a deductive argument, then the conclusion is certainly true. But if your premises are just probably true, then they are inductive, and so the conclusion is only likely.
It is evident that if history is to be probabilistic, then the historian is faced with the problem of how he certainly knows what he does. The inductive argument, due to its probable nature, is unable to encompass every instance of a class of things. If I say that all doves are white, then this statement could not be an probabilistic one, since the statement is about the certain totality of doves and to know all doves are x, is to have a truth probability of 100%. But to have 100% certainty is against the nature of probable conclusions which can only very from .0001-.9999 integrals of certitude. The contrary is true of the deductive argument. But the whole reason for history is to know the totality of all particular events inasmuch as these occurred. So the inductive method is not a useful historical method, since if a method can fulfill the purpose of a science, then it is useful, but induction doesn't fulfill the reason for history, so it isn't useful by simple modus tollens. But again, if something impedes you in the attainment of a goal, then it is a problem. But induction impedes the goal of finding every past event, so finally induction is a problem for the historian. But if induction is ruled out, what other choice do we have? In fact, we have only one other choice and this is the method of deduction. Deduction, as was explained, takes certain premises and argues toward certain conclusions. As such, it is possible to deduce statements that apply to all members of a class of things. These statements are called "universal". And since deduction can do this, and since history consists in the aim for the universal, then deduction is the best method for doing history. And for much the same reasons, deduction is also the most useful historical method. Having established this, we have also found the answer to the first problem of the historian, "how do I know what I know is true?" And here we answer that since deduction is a way of knowing, and since it establishes certain conclusions, we can conclude that it establishes knowledge and certain conclusions. But all conclusions are a type of knowledge -since conclusions are known and everything known is knowledge and therefore deduced conclusions are knowledge and further are the best kind of knowledge; they are certainly true statements.
What I would now like to share with you are some of the fruits of deductive history. Now in teaching and learning, it is meet to proceed from what you know more to what you know less. I personally, know more about American history than anything else, so I begin my analysis from that subject. The analysis deduces several new conclusions from several old facts. The first fact is that all english national projects were executed through the agency of Elizabeth I, the second is that all English merchants were the proximate executors of these projects (Sir Francis Drake for instance), and the last fact is that, some puritans were English merchants. It follows then, that some puritans executed Elizabeth's will. More controversial theses can be proved presently.The first premise is that all white people didn't like slaves, the second is that some white people were slaves, and so the conclusion is that some slaves didn't like slaves. This is highly surprising because most people tend to see the slave class as homogeneous in both its attitudes as well as its racial makeup. But even now, in high school texts, this idea has been effectively combated for instance, slaves coming from one African kingdom frequently disliked slaves from another and slave-on-slave hatred is proved again from a different premise (if you think that only blacks were slaves). Yet another thesis can be derived about the class-conflicts of American history. For instance, All high officeholders were rich men, all rich men engrossed land, so all high elected officials engrossed land -something that people generally don't see in the character of democratic government, yet such were the politician's actions. For a final controversial thesis, I would argue that black men had important social functions in colonial new England. According to some texts, all new england men were powerful patriarchs who transacted the important work of the society while their wives transacted the domestic work. But some males in new england were black (since there were some black slaves -mainly butlers -who resided in new england), so some blacks transacted socially important work. This and all the other conclusions which have been derived, are absolutely demonstrated and may be called apodicitic knowledge.
What then, is to guide the historian's research -our last query. Now no historian can escape having a point a view because if he tried to argue against having a point of view, he would be taking a point of view. But a point of view, taken as a preconceived guide, is essentially a research paradigm. So no historian can escape having a research paradigm. Further every research paradigm should be useful and as we saw earlier, the most useful thing is that which does not impede the approach towards the goal. But as we saw above, deduction is the most useful method. So we know that deduction is useful, however we cannot be sure that it is a research paradigm, even though all research paradigms are useful. So then how do we solve this logical problem? The solution is that since there are only two choices between useful methods, induction and deduction, and since induction is not useful, clearly only deduction exists in the category of "useful methods", at least for history. Hence all research paradigms in history must be deductive in character.