Science has long acknowledged a clear and yet seemingly paradoxical relationship between Psychology’s understanding of the abstract mind and Neurology’s understanding of the material brain. Psychology observes our minds to lie to us for our own good, but such behaviour is incomprehensible when we consider Neurology’s observation of the brain being comprised of chemicals and neurons. How can science offer two seemingly incompatible results as true, and still be considered as logical? The answer may appear when we consider the similarities and dissimilarities between Rene Descartes’ and John Locke’s understanding of truth and logic in the Early Modern Period. Descartes and Locke, like Psychology and Neurology, offer seemingly incompatible conclusions: Locke believed that humans are born without any innate ideas, and so all knowledge is necessarily based on experience, including our knowledge about the truth and existence of logic, whilst contrarily, Descartes argued that all experience based knowledge is susceptible to doubt and that we are born with innate ideas about logical truths, and it is through logic alone that undoubtable truths are formed. This paper claims that when it is identified that Descartes and Locke are offering two different interpretations of truth and logic, it can be observed that the differences found in their results reflect only the interpretive differences found in their utilisation of truth and logic. Therefore, they are not in disagreement about the nature of reality, but rather about the method we use to understand the nature of reality-just like contemporary Psychology and Neurology.