indubitably

epäilyksettä, kiistämättömästi In a manner that leaves no possibility of doubt; undoubtedly.
1871, w:Thomas_Hardy Thomas Hardy, Desperate Remedies, ch. 18:

Now his first suspicion was indubitably confirmed.

The world is indubitably one if you look at it in one way, but as indubitably is it many, if you look at it in another. It is both one and many—let us adopt a sort of pluralistic monism.