Quotessence
Home / Books / The Grand Design

The Grand Design

Book by Stephen Hawking · 2 quotes · Universe, Life, Big Questions

Filter quotes by topic

AllUniverseLifeBig QuestionsBeginning Of The UniverseDeterminismFree WillNothingPhysicsRealityAlternative HistoriesBeginningBig BangBig Bang TheoryBlack HolesBodyConceptEnergyEnvironmentExistenceFeynman

The Grand Design Quotes

“How can one tell if a being has free will? If one encounters an alien, how can one tell if it is just a robot or it has a mind of its own? The behavior of a robot would be completely determined, unlike that of a being with free will. Thus one could in principle detect a robot as a being whose actions can be predicted. As we said in Chapter 2, this may be impossibly difficult if the being is large and complex. We cannot even solve exactly the equations for three or more particles interacting with each other. Since an alien the size of a human would contain about a thousand trillion trillion particles even if the alien were a robot, it would be impossible to solve the equations and predict what it would do. We would therefore have to say that any complex being has free will—not as a fundamental feature, but as an effective theory, an admission of our inability to do the calculations that would enable us to predict its actions.”

LifeUniverseFree WillDeterminism
Book:The Grand Design
Create image

“Though we feel that we can choose what we do, our understanding of the molecular basis of biology shows that biological processes are governed by the laws of physics and chemistry and therefore are as determined as the orbits of the planets. Recent experiments in neuroscience support the view that it is our physical brain, following the known laws of science, that determines our actions, and not some agency that exists outside those laws. For example, a study of patients undergoing awake brain surgery found that by electrically stimulating the appropriate regions of the brain, one could create in the patient the desire to move the hand, arm, or foot, or to move the lips and talk. It is hard to imagine how free will can operate if our behavior is determined by physical law, so it seems that we are no more than biological machines and that free will is just an illusion.”

UniverseFree WillDeterminism
Book:The Grand Design
Create image