Sentence:  Doubtlesse, in the "Idaea", or mentall shape before it come as it were into act, by beeing painted, cut, or carued, those terminating, and truly "Mathematical" lines, <WSD>abstractedly</WSD> considered, are manifest, adhering (or inhering rather) without any possibility of separation from the conceaued Image. 
Meaning of the word marked with <WSD> tags:  In an abstracted manner; separately; in the abstract. (First attested in the early 17th century.)<ref name=SOED>(page=10)</ref>