Introduction and History of Psychology
Chapter 1
Foundational Ideas from Antiquity
Greek Philosophers
● Socrates
○ Founding father of philosophy
○ Asked questions and made people get to the answer themselves → Plato (his
pupil) interpreted this as nativism: people already know the answer to the
questions deep inside
○ Plato also said that Socrates was a rationalist → rationalism: we acquire
knowledge through reasoning
● Plato
○ Socrates’ student
○ Idealism: we experience the world
outside of us through our senses (but our
sensory input is imperfect) → the world
we perceive is only a world of
appearances, the real knowledge about
how the world works comes from the
ideal form
■ Idealism → true knowledge is in
your mind/soul, not in the world
around you
○ Allegory of the Cave: the way the prisoners perceive the world from the
shadows they see are the appearances, the ‘real’ world that prisoners see after
they’re released would be the ideal form
● Aristotle
○ Plato’s student
○ Empiricism: observations + classification (taxonomy) = knowledge
○ Aristotle’s classifications:
■ Vegetative souls: nourishment, reproduction
, ■ Sensitive souls: sensation, locomotion, memory, imagination
■ Rational souls: logical reasoning
Islamic Philosophers
● Al-Kindi
○ Arabic numerals
● Alhazen
○ Book on optics and visual perception
○ Camera obscura → light reflections are flipped upside down
● Avicenna
○ Extended the idea of Aristotle’s functions of the soul
■ Exterior senses (vision, hearing, smell, taste, touch)
■ Interior senses (common sense, imagination, memory, estimation,
appetition)
○ Self-awareness → floating man thought-experiment
■ Self-awareness exists independent of sensory input
Chapter 2
Pioneering Philosophers
René Descartes
● The only way to develop true knowledge is to doubt everything
● He looked for simple natures: things you know for sure are true
● According to Descartes, knowledge was more about thinking (deduction) than sensory
experience (induction)
● Physical world: extension and motion → things have a certain space and a certain
movement
● Link to Plato → idealism (appearance vs ideal form)
● Physics: the universe is filled with particles (fire, air, earth)
○ These particles have extension and motion
● Mechanistic Physiology: seeing the body as a machine
, ○ Descartes thought that the body could be fully explained in mechanical terms
(there was no soul possible)
○ Descartes thought that nerves are hollow, and that they are filled with animal
spirits (cerebrospinal fluid)
○ Reflex = stimulus (external world) + response (organism behavior)
■ Automatic reflexes (when you touch something hot, you pull away)
■ Acquired reflexes (reflexes you learn, driving a car becomes automatic
at some point)
■ Descartes was able to explain the interaction between the internal and
external world without a soul
■ Unlike Aristotle, who tried to explain that plants, animals, and humans
have different souls
● You can doubt all of your senses and thoughts, but you can’t doubt that there is
someone doubting it → I think, therefore I am
● Rational soul with innate ideas → independent of the outside world
● Body and mind are two different things
○ Material body and immaterial soul that interact in you
○ Related to Plato: nativism and rationalism
○ Related to Avicenna: floating man thought experiment
■ Self-awareness is a characteristic of the rational soul, independent of
sensory input
● Elizabeth of Bohemia
○ How do the material body and the immaterial mind interact?
○ Descartes: through the pineal gland → located in the ventricles (the spaces in
the brain where the CSF flows)
■ The body is double (2 eyes, 2 arms, 2 legs, etc) but the soul is one →
the pineal gland is also one thing
■ Interactive dualism: sensory input comes into your body
automatically → it makes the CSF flow → it moves the pineal gland
and creates experiences in the mind
■ Images are reversed in the eyes (camera obscura, Alhazen)
