It is true that a well-written paragraph should be coherent and unified. These characteristic are some of the most important ones when it comes to writing essays.
Each paragraph in a dissertation should be: 1) Unified: all sentences must refer to the main idea (or thesis) of the dissertation; 2) Coherent: sentences must be organized in a logical way and must follow a defined development plan; 3) Well developed: each idea discussed in the paragraph should be adequately explained and supported through evidence and details that work together to explain the central idea
