In the body of the document, you can use two paragraph styles, one that provides the numbering ("Chapter IV" in your example) and another that provides the text ("Life and Works").
In the TOC, you include only the second paragraph style which will then be unnumbered. To fix that, you add the "Chapter #" number format to the corresponding TOC style.
See
http://wordfaqs.mvps.org/TOCTips.htm#UnnumberedHeadings.