Charades

My first though your House from the thief it defends,
 Like a knave or a cheat you abuse and despise,
My second though small yet alas comprehends
 All the good, all the great, all the learn’d all the wise.
Of my third I have little or nothing to say
Except that it marks the departure of day.

My first is the lot which is destined by fate
For my second to meet with in every state
My whole is by many philosophers reckoned
To bring very often my first to my second.

Porson