It is important to specify that in the domain of positive sciences, fundamental models generally accepted do exist. One of these models is e.g. Newton's Mechanics. As this model generates a reality, all physicists consider that the 'reality' is the one generated by Newton's Mechanics, within its limits of applicability. Due to reasons associated to confusions of the science of knowledge, the reality generated by Newton's model is considered as 'objective'. Thus, "objective reality" is a term generated by a generally accepted model in specified conditions. From this point of view, the fact that the Sun revolves around the Earth is an "objective truth", at least at the level of the year 1500. It needs to be stated by all means that without a model, the external reality cannot be perceived. After building a model associated to the external reality, what we perceive is what the model states as perception. If, e.g. we say that 'snow is white', this is the result generated by a model associated with external reality, external reality which contains the element 'snow'. One of the properties of the element 'snow' is that it is white. Under the microscope (another model) the same snow looks transparent. As we already mentioned, reality is the one generated by the model associated to a given external reality. Each time we state a truth, we have to specify first the model. Example: There are an A and a B person. A is taller than B, as it results from measurement. The term 'length' is generated of the model 'space', as Euclid's Geometry and Newton's Mechanics understand it. These fundamental models characterize this truth as objective. If we say that "A is more attractive than B", this is a subjective truth. However a model has also generated this truth, more or less elaborate/ specified and more or less accepted by different persons. The conclusion is that the term 'subjective truth' is resulting from a model, which is not unanimously accepted or insufficiently elaborated. In this case, it is clear that people should avoid such truths or should declare the model. With the evolution of thinking, the term 'subjective truth' will be removed from the thinking system. ETA 3: Fundamental problems associated to scientific knowledge Computers are known as devices used to play complex games based on intelligence, to write texts of different types, to make calculations, to store and manage data, to send or receive information, to build and operate symbolic models, etc. A question occurs however: which is the principle of work of a computer? If we do not interact with the computer via a primary programming language (Assembler or machine language), I believe that it is impossible to find the principle of work of the computer either from in- or outside of it. The fundamental function of a computer is to do logical and arithmetical operations with binary numbers with the help of an electronic device (register) called 'accumulator'.