The article examines George Berkeley’s philosophy of the 1730s, a period that is seldom analyzed by commentators. The article puts forward two theses. First, in 'Alciphron’ (in particular, in dialogues IV and VII) Berkeley offers a new metaphysics in comparison with immaterialism, which can be described as descriptive, using P.F. Stroson's terminology. Second, in Berkeley's philosophical system, 'Alciphron’ should take the first place — the place of introduction. These theses are supported by analyzing the argument for the existence of the Christian God, presented in the fourth dialogue. The article shows that this argument, which is considered by most researchers only as plausible, can be strengthened by referring to the content of the seventh dialogue. The analysis of the seventh dialogue shows the importance of the so-called natural notions for Berkeley's argumentation in 'Alciphron’. Natural notions are accepted by us without any theoretical justification, they are rooted in human nature. Such natural notions include the concept of accountability. It is connected to many other concepts that characterize our attitude to the actions of free agents (for example, guilt and merit). Our reactions to human actions are similar to reactions to the language of the Creator revealed to us in nature (in the case of God our reaction is praise based on admiration for nature). Natural concepts underlie Berkeley's descriptive metaphysics, the main idea of which is that we cannot but consider phenomena as the result of the actions of free rational agents (finite and infinite). This is justified by a transcendental argument: the condition for the existence of society is belief in natural concepts; society exists and is a natural state for man; therefore, we believe in natural concepts. The use of transcendental argumentation supports the thesis the metaphysics of 'Alciphron' is descriptive.