In the last part of this course, we talked about how science is conducted, but we didn't cover why it's conducted, and I bet the answer to this question seems obvious, to learn about the world of course. What else could it be? As a philosopher, part of my job is to analyze some of our deepest held assumptions. So let's pause for a moment to think about what it means to say that science aims to learn about the world. The keyword here is aims. Scientists certainly aim to uncover truths about the world, but are we sure that science does in fact tell us what the world is really like? Scientists have been wrong in the past, so how do we know that they're not wrong now? In one sense, this is what philosophers mean when they say that science is objective. Scientific knowledge is objective if it tells us what the world is really like. This is opposed to some particular scientists subjective take on the world, some particular point of view, but this isn't the only thing philosophers mean when they say that science is objective. We also debate the objectivity of the scientific process itself. When we talk about objectivity in this sense, we're asking questions about whether scientists and their methods are unbiased. In the last part of the course, we talked about the second sense of the term objectivity. Objectivity as it relates to the scientific process. For example, we talked about how observation is the foundation of science because observation is public. Public observation should, at least in theory, cancel out any one person's desire to see what they want to see. We also talked about how clinical trials are randomized and double-blind to avoid bias,. These two senses of objectivity are related. The hope is that in unbiased scientific process will lead to knowledge about what the world is really like. So how is this possible? In my view, science gains some of its objectivity, in both senses of the word, by its social organization. When scientists put their minds together, when they combine their individual viewpoints, they help to rid science of bias. This is how the social structure of science or the fact that science is conducted by communities can help the scientific process become more objective. Let me try to further illustrate this point by telling you the classic story about the blind men and the elephant. There are many versions of this parable, all with different morals, but here's the version I like best. Long ago, a group of blind men heard that a traveler had brought in a large unusual animal, an elephant, to their village. They had heard stories about these animals but none of them had ever met one in real life. Curious about what elephants were like, the men went to where the animal was being kept, and when they got there, they asked the traveler if they can each inspect the elephant with their hands since they couldn't see it. The first man grasped the elephant's trunk and declared that elephants are like snakes. Another man touched the elephant's ear and claimed that the animal was like a fan. A third men petted the elephant's leg and announced that it resembled the tree, while a fourth man touched the elephants side and claim that it looked like a wall. A fifth grasp the elephant's tail and said that the elephant resembled a rope, and the last man felt the elephant's tusk and concluded that the animal must look like a sphere. After the last man held petted the elephant, the animal grew nervous and the traveler took it away, and so the five-men were left with very different impressions of what elephants are like. Recognizing that they'd each touch different parts of the animal, they put their knowledge together to figure out what elephants are really like. They realized that it must be a large animal with fan-like yours, tree-like legs, a snake-like trunk, a rope-like tail, and so on. Only together, not alone, could they get closer to understanding what elephants are really like. So what is the moral of this story, and what's it got to do with science? Only collectively can scientists get closer to understanding what the world is really like. They combine their subjective experiences to patch together objective knowledge of the world, and only collectively can they cancel out each other's individual biases.