在法律發展史上，法治概念一直被視為是法律體系成熟度的指標。其理解方式可由兩方面加以說明。第一，從形式及文義上言，法治就如其字面上之義。通常即以「以法治理，非以人治理」說明之。然而此所稱之法，究何所指？實證法或自然法？此乃理解法治概念與功能之關鍵所在。通常多以實證法說明法治。因此，國家所通過之法即為管理國家事務與解決爭端之依據。於此意義下，民主制度之內涵與運行機制即與法治有密切之關係。第二，從法律推理之意義觀之，法治含有如何導引出具客觀性與可認知性之判決之義。由於判決之作成係基於法律，而且具有合理之理由，因此，人為誤差、獨斷、任意等因素即可排除。判決即得加以批判、檢討並基於法治原則訂正、修改。 這似乎就是法治之真諦。法治概念主要係有關法之客觀性問題，因此，法治亦可視為理性法則。於此意義下，人性尊嚴之客觀價值即可作為形式概念法治觀之實質內容，以使法律推理一方面不違客觀性，他方面其判決亦能具有合理性。因此，即使法治以形式意義觀之，卻非可謂其毫無意義或內容可言。

On the history of legal development, rule of law has been an indispensable element for the proper function of a legal system. The reasons for this conclusion may be described in two ways. First, literally, the conception of the rule of law means what it says. It is often expressed by the phrase“government by law, not by man". However, what does the “law" mean in that context? Does the “law" refer to positive law or otherwise? This is the crucial point in interpreting and understanding the value and function of the rule of law. More often than not, rule of positive law is thus understood. In this instance, the conception of the rule of law is contingent on the institutions and mechanism of democracy. Secondly, in the sense of legal reasoning, the rule of law connotes the possibility of producing a decision objective and comprehensible. Since the decision is based on the law and explained with reasoned reasons, arbitrary and capricious human equation is ruled out from the process of decision­making. The decision is susceptible to review and to be corrected under the principles of the rule of law. Seemingly, this is the genuine interpretation of the conception of the rule of law. The idea of the rule of law concerns mainly with the objectivity and predictability of law. In this sense, the rule of law is regarded as the rule of reason. In this connection, the universality of human rights may provide for the rule of law as substantive criterion in order that the decision can be both objective in form and an end in itself. Accordingly, even the rule of law may be understood in formal sense, nevertheless, it is not an idea without any substantive content.