> However, I do have an issue with his focus on applying science in the definition, even though it doesn't come across in his final conclusions

I don’t think it’s about science. It’s about the scientific method. From wikipedia

  The scientific method is an empirical method for acquiring knowledge through careful observation, rigorous skepticism, hypothesis testing, and experimental validation

You don’t have to have a full theory or model to follow. You also can follow your intuition and use your creativity. You just have to carefully compare your results to your goal.