"he who would do good must do so in minute particulars"

what does the following phrase by william blake mean? and how do we use it?...
"he who would do good must do so in minute particulars"

This is just a guess. Maybe it means if you want to do good for society at large, you must also do good on a personal, intimate basis. Like the old Three Dog Night song, Easy to be Hard:

"...How can people have no feelings
How can they ignore their friends
Easy to be proud, easy to say no

Especially people who care about strangers
Who care about evil and social injustice
Do you only care about bleeding crowd
How about a needing friend, I need a friend..."

But I could be wrong.

The full quote (from brainyquote.com) is "He who would do good to another must do it in Minute Particulars: general Good is the plea of the scoundrel, hypocrite, and flatterer, for Art and Science cannot exist but in minutely organized Particulars." William Blake. Pamela

At the Miss America pageant (remember that?) they would ask he contestants some question or other to which the answer was often something like "work for world peace." The next logical question would have been, "And where will you start?" In practice, one does good (or sometimes evil) in particular steps, in increments, large or small. The doctor doesn't wish me well and then go away, he cuts open my stomach. The nurse doesn't just say, "I hope they all get well"; she changes their dressings and brings them a glass of water.
SS