Michael Faraday coined the term " magnetic field " in his Researches when postulating, after discovering that all the constituent materials of a human are diamagnetic, that if a human were set in a sufficiently strong magnetic field then they too would align with the field. Faraday did not conceive of this field as a mere mathematical construct for calculating the forces between particles—having only rudimentary mathematical training, he had no use for abstracting reality to make quantitative predictions. Instead he conjectured that there was force filling the space where electromagnetic fields were generated and reasoned qualitatively about these forces with force lines: