"Nothing in the mind..." This refers to all the content of our mental world – our beliefs, thoughts, concepts, memories, etc.
"...which was not first some manner of senses..." This highlights the origin of this mental content. It claims that everything we think, feel, or know originates from our senses (sight, hearing, touch, taste, smell).
What it means:
* Sensory foundation: We don't have innate, pre-existing knowledge. Our minds are essentially blank slates at birth, and we build our understanding of the world through our senses.
* Experience is key: We learn and form our opinions based on what we experience. The world is constantly bombarding us with information through our senses, and our minds process and interpret this data to form our perceptions and knowledge.
* No independent ideas: Empiricists argue that there are no "innate ideas" – ideas that we are born with, independent of experience. All our concepts and thoughts are built upon the foundation of our senses.
Examples:
* Imagine a baby learning the word "dog." It sees a dog, hears someone say "dog," and touches the dog's fur. Through this sensory experience, it forms a mental concept of what a dog is.
* Our knowledge of colors is based on our visual experiences. Without our eyes, we would have no concept of red, blue, green, etc.
Important Note: While empiricism is a powerful and influential philosophy, it's not without its critics. Some argue that certain concepts, like mathematical principles, exist independently of sensory experience.
Overall, the statement "there is nothing in the mind which was not first some manner of senses" captures the central belief of empiricism: our knowledge is fundamentally derived from our sensory experiences.