How Much Should We Work?
The first step to answering this question is to define work.
If you define work as "that activity that you do to produce income," then the answer is:
Work as much as you need to in order to earn: the amount you need to spend in order to be happy + the amount you need to save for future requirements.
Now let's define work a different way. In physics, work is a measure of energy transfer.
Instead of correlating work with compensation, let's instead tie it to energy.
Now let's ask the question again - how much should we work?
Or put another way, what percentage of my time should I expend energy to pursue something good?
This is a much more powerful question, as it allows us to think of other things that we need to do, and should consider, as work. It allows us to put effort into every area of our lives.
We need to create meaningful relationships with our children, for example. We are happy when we consciously consider this, and will ourselves to act on this need.
Put another way, we need to "put in the work" on every aspect of our lives. We need to build relationships, learn about the world, be active, enjoy friends, and generate income.
Considered holistically, our work is everything meaningful in our lives into which we can and should put energy. So how much should we work? The answer is easy: 100% of the time we are awake in this world.