To add another perspective to the discussion, Yegor Bugayenko (author of the Elegant Objects books) says that splitting data and data manipulating objects are "

To add another perspective to the discussion, Yegor Bugayenko (author of the Elegant Objects books) says that splitting data and data manipulating objects are "pure evil" because when you do it that way it is going against OOP as you will get functions and data to operate on. Which is exactly where we were before OOP. If you can get over of him calling everything "pure evil", the simplicity he tries to achieve with his controversial view on what is true OOP is quite interesting. I think that instead of this splitting to data and functions a better solution is to use Single Responsibility, Tell don't Ask, and Demeter's law. This way one can make classes small enough so functionality accumulation won't be a problem and a class will tell what to do only to their "neighbouring" classes. This way every change in the code will be somewhat local. Of course this is an idealistic view which fades with every ORM entity read... :)