Since Tarski proposed to take keeping invariant under all transformation as the stan-dard of logical notions,people have put forward successively alternatives such as keeping invariant under isomorphism,homomorphism and potential isomorphism.This way of investigation is to give algebraic characterization from the perspective of formal seman-tics,which is accurate but cannot fully reflect the logical conception having existed in our mind.By analyzing Frege's argument,we can reasonably infer that the essence of logical constants is to describe Truth and then obtain Fregean standard.There are two types of logical constants in terms of Fregean standard.One is truth functions,which take Truth as the description object.The other is to take the predication as the descrip-tion object,and can be reduced to the fundamental logical relation.The second is just the quantifiers,which characterize"Wahrsein".Fregean's standard deepens our under-standing of logic and the relationship between logic and philosophy.we obtain a very different understanding of the membership,mode and norm from the popular view when applying the standard to analyze them.
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