> Whether a field is modifiable is often determined by the current user's access level and the current state of the object. So, putting such restriction at the

> Whether a field is modifiable is often determined by the current user's access level and the current state of the object. So, putting such restriction at the function definition may have made things too rigid. True, let me try to clarify. There might be some attributes like `admin` that you don't want twiddled via the `update` method but rather mutated via a setter function. In this case, the signature of the `update` function would be helping to indicate that. (A better example might be the attribute `active` with two methods called `activate` and `deactivate` that send emails and what-not.)