Example Postulate: Accessorium non ducit, sed sequitur, suum principale

In simple terms, this postulate states that an auxiliary participant in a criminal offense does not have a leading role, but follows the instructions or actions of the main perpetrator. This principle is an important part of criminal law, especially in the concept of joint liability.
In criminal law, two forms of participation are generally distinguished: independent participation and non-independent participation. Stand-alone participation is when each participant is judged and tried based on his or her own role in the criminal offense. Non-independent participation occurs when a participant's liability depends on his or her role in the crime committed by the main perpetrator, as well as whether the main perpetrator's actions are considered a criminal offense.

In this context, stand-alone participation involves the perpetrator acting alone or together with the main perpetrator. Non-independent participation involves those who encourage or assist the main perpetrator. They serve as assessors for the principal, and their liability is dependent on the liability of the principal.
In the Netherlands, this concept was adopted by several criminal law experts and drafters of the Dutch Criminal Code, such as Simons, van Hamel, and wetgever (legislators).

However, some jurists have different opinions regarding this division. They argue that in modern criminal law, a person's liability should be determined based on his or her own role independent of the actions of others. However, the history of the formation of the Criminal Code shows that there is a concept of independent participation and non-independent participation.

Pompe's argument emphasizes that all forms of inclusion are not mutually exclusive, although the role of each participant must be assessed individually. This opinion is supported by van Bemmelen, van Hattum, and Moeljatno. They argue that the participants form a single entity. In addition, another principle that supports the separation of stand-alone and non-stand-alone participation is res accessoria sequitur rem principalem, which means that the accomplice follows the principal.