The Single Responsibility Principle is based on the high cohesion principle. The difference between the two is that a highly cohesive classes features a set of responsibilities that are strongly related, while classes adhering to SRP have just one responsibility.
But how do we determine whether a particular class features a set of responsibilities and is thus just highly cohesive, or whether it has only one responsibility and thus adheres to SRP? In other words, isn't it more or less subjective, since some may consider a class very granular (and as such will believe the class adheres to SRP), while others may consider it not granular enough?
Best Answer
Why yes it is very subjective, and it is the subject of many heated, red-faced debates programmers get into.
There's not really any one answer, and the answer may change as your software becomes more complex. What was once a single well-defined task may eventually become multiple poorly-defined tasks. That's always the rub too. How do you choose the proper way to divide a program up into tasks?
About the only advice I can give is this: use your (and your coworkers') best judgement. And remember that mistakes can (usually) be corrected if you catch them soon enough.