Below are the types of action a philosopher can use.
A Standard, or Basic Action is an action that consumes a turn, typically something like attacking or defending.
Ongoing is an ability with a fixed duration, usually has another action type that determines how it triggers.
Counter Actions are quick actions that can be triggered in the midst of battle usually by an attack, this may consume the Philosopher's next turn.
A Free Action is an action that is considered to take up no time or effort for the philosopher, such as talking and other minor actions. Thinking and talking simultaneously would technically count as a Standard Action for any real philosopher, but it’s okay to suspend disbelief a bit. DMs may rule that certain, otherwise free actions may only be performed once per turn, such as picking up an object. This is optional and up to the DM's discretion.
A Passive Ability isn’t an action per se, but it still has an effect on the philosopher’s performance. Such abilities become active the moment they are acquired and keep functioning constantly. These are usually created by divine auras, unshakable beliefs or beneficial items.