What is the distinction between legislative and judicial functions of administrative law?

The distinctions between legislative and judicial functions of administrative law are as follows:-

In Prentis Vs. Atlantic Coast Line Co. (1908) 211 US 210, Justice Holmes points out that the distinction between legislative and judicial functions in the following words-

“A judicial inquiry investigates, declares and enforces liabilities as they stand on present or past facts and under laws supposed already to exist. That is its purpose and end. Legislation on the other hand looks to the future and changes existing conditions by making a new rule to be applied thereafter to all or same part of those subject to its power”

So, according to him the main aspect is the element of time. A rule (legislative function) prescribes future pattern of conduct and creates new rights and liabilities, whereas a decision (judicial function) determines rights and liabilities on the basis of present or past facts and declare the pre-existing rights and liabilities.

In the words of Green, “The legislative function then is general and relates to the future, whereas the judicial function is specific, final and ordinarily relates to the past”.

Again, element of applicability should be taken into consideration.

Professor Dickinson says- Legislation affects the rights of individuals in the abstract and must be applied in a further proceeding before the legal position of any particular individual will be definitely touched by it, while adjudication operates upon individuals in their individual capacity.  

Mr. Green again says, “Perhaps it would be better to say that it is a legislative function to make all substantive law and a judicial function finally to determine constitutional jurisdiction and the application of substantive law to specific facts.”

These tests may create some problems in certain cases. The problem is to be solved by considering the function and determining its character in each case.

The rules of natural justice don’t run in case of legislation, but in case of judicial function following principles of natural justice is a must.

Again, the requirement of publication and consultation should be followed in case of legislative function but in respect of judicial function this is not so.

Lastly, duty to give reason applies to judicial function but not legislative orders.