To ensure that enterprise information systems are effective, the information systems division of an enterprise must clearly specify its requirements for the entire system, not just the software to be constructed. The information systems cycle is the continuous course of action by which enterprise information systems are constructed. It is important that the owner of the information systems specify his proto-requirements, defined as the requirements of the information systems, at an early stage of the cycle. This paper discusses how pattern language, a concept from architectonics, can be used to stipulate proto-requirements. In software engineering, applications based on pattern language have produced significant results in many books, including the Design Patterns. However these applications only focused on the aspect of the pattern format of pattern language. Originally, the concept of pattern language means continuous activities for building, which are called the timeless way. In information systems engineering, when focusing on this aspect, pattern language could be regarded as a mechanism to incorporate the requirements and design constraints of information systems into itself as organizational learning.