Beauty

The beauty of the science of the law is also expressed in the fact that it contains many subtle distinctions. Studying the law can therefore make a habit of watchmaking looking at reality (but you have to shave with Ockham’s razor). An example of subtle and , importantly, very practical distinctions are the characteristics of a judicial decision:
(a) THE EFFECTIVENESS OF THE JUDGMENT (fitness for effect)
(b) THE ENFORCEABILITY OF THE JUDGMENT
(c) THE FORMAL FINALITY OF THE JUDGMENT (NON-APPEAL)
(d) THE SUBSTANTIVE LEGITIMACY OF THE JUDGMENT (binding force of a formal final decision) and
(e) RES iudicata.

The distinction between substantive legitimacy and res iudicata is governed by separate provisions, but it is probably not a mistake to say that res iudicata is essentially a narrower aspect of substantive legitimacy. This was meant by the Supreme Court in resolution III CZP 3/18, in which it placed a sign of equality between substantive legitimacy and res iudicata. But strictly speaking, there is no sign of equality. In English law, res iudicata is part of the broader concept of ESTOPPEL: it means situations in which it is prohibited (is estopped) to refer to claims contrary to previously established or declared. English law is more subtle here.